Compositions comprising chlorosulphonated polyethylene, carboxylated butadiene-acrylonitrile and magnesium oxide useful for liners or membranes

Abstract

Improved compositions, and liners and membranes produced therefrom, are provided which comprise a mixture of chlorosulphonated polyethylene and carboxylated butadiene-acrylonitrile polymer. Such compositions have use as improved liners and membranes for reservoirs and pits or ponds.

What is claimed is: 
     
       1. An improved liner or membrane composition characterized in that it comprises from about 90 to about 55 parts by weight of chlorosulphonated polyethylene and from about 10 to about 45 parts by weight of carboxylated butadiene-acrylonitrile polymer, for a total of 100 parts by weight of polymers, said chlorosulphonated polyethylene containing from about 38 to about 42 weight percent of chlorine and from about 0.9 to about 1.1 weight percent of sulphur and said carboxylated butadiene-acrylonitrile polymer being a solid polymer having a Mooney (ML 1+4 at 100° C.) of from about 45 to about 70 and containing from about 25 to about 30 weight percent of acrylonitrile and from about 5 to about 10 weight percent of an unsaturated carboxylic acid monomer, and said composition also contains, per 100 parts by weight of polymers, from about 3 to about 7 parts by weight of magnesium oxide. 
     
     
       2. The composition of claim 1 characterized in that it also contains, per 100 parts by weight of polymers, from about 40 to about 80 parts by weight of carbon black or from about 30 to about 60 parts by weight of carbon black plus from about 10 to about 20 parts by weight of mineral filler. 
     
     
       3. The composition of claim 2 characterized in that it also contains, per 100 parts by weight of polymers, from about 0.5 to about 3 parts by weight of sulphur containing accelerator. 
     
     
       4. The composition of claim 3 characterized in that the sulphur containing accelerator is one or more of mercaptobenzothiazole, benzothiazyl disulphide and dipentamethylene thiuram tetrasulphide.